This invention relates to means for providing pin alignment and protection in a cathode ray tube-base assembly and more particularly to a protective cap having discrete means for providing alignment and protection for a protruding array of tube pins at least one of which is spatially encompassed within a substantially tubular isolation structure of the associated base member.
Advancement in cathode ray tube technology, in particular the tube types utilized in television and allied display applications, has produced efficient compacted electron gun structures which are incorporated in tube envelopes having reduced neck diameters. The operating potentials for the various elements of the gun structures are supplied via an annular array of connector pins sealed into and projecting from the stem closure portion of tube. As the neck diameters and associated closure-portions become smaller, the spacings between the connective pins decrease in a proportionate manner.
Many types of these tubes evidence large voltage differentials, i.e., in the order of 5 KV to 12 KV, between certain of the connector pins. Therefore, it has been found advantageous to incorporate a form of arc protection into the tube base and socket combination. Base and socket means have been provided in the art to minimize inter-pin arcing wherein at least one of the vulnerable high voltage pins is tubularly encompassed by one or more spatially related isolation structures integrally formed as part of the base member. In conjunction therewith, a compatible socket member contains receiving means to mate with the respective tubularly encompassed pin, thereby effecting an isolated high voltage connection which has been found to be very effective in controlling deleterious arcing.
Unfortunately, the isolated pin, positioned within the protective tubulation, sometimes is bent out of alignment during tube basing or as a result of subsequent tube mishandling. Once this happens, there is no facile way of straightening the pin due to the narrow dimensioning of the surrounding tubulation.
To prevent the pin from being deleteriously bent, a separate removable pin aligning insert has been devised to slidingly fit within the pin-accommodating tubulation. Such insert means, having a longitudinal bore therein to protectively encompass the respective pin, is dimensioned to snugly fit within the tubulation and be frictionally retained therein until removed prior to subsequent tube utilization. While the separate snug-fitting insert affords protection for the isolated pin, it is an individually handled unit and evidences no cooperative construction with any other base protective means. The retention of the insert is controlled by the external dimensions of the insert in conjunction with the internal dimensionings of the tubulation.